Internal model-based tracking of a servo gantry system with frequency-varying references

This paper presents an internal model-based tracking control for a class of nonlinear systems driven by frequency-varying references. It is shown that if the error-zeroing input is polynomial of exosystem state, a linear time-varying internal model can be utilized to generate higher order modes of the exosystem. The proposed control design is applied to a high precision servo gantry system to track frequency-varying references. A numerous experiments are conducted to demonstrate the significant improvement of the tracking performance with higher order internal model.